A person covers a distance of 60 km from A to B at a speed of 20 km/h and returns from B to A at a speed of 30 km/h. What is his average speed for the entire journey?

Correct option is B

 
Given:
- Distance from A to B = 60 km
- Speed from A to B = 20 km/h
- Speed from B to A = 30 km/h
Formula Used:
Average speed for a round trip = 2 × Distance / (Distance/Speed A to B + Distance/Speed B to A)
Solution:
1. Calculate time taken from A to B: Time A to B = 60 / 20 = 3 hours
2. Calculate time taken from B to A: Time B to A = 60 / 30 = 2 hours
3. Total distance = 60 + 60 = 120 km
4. Total time = 3 + 2 = 5 hours
5. Average speed: Average speed = 120 / 5 = 24 km/h Answer: (b) 24 km/h